ABSTRACT: Diabetes Models Phenotyping Core The Diabetes Models Phenotyping Core of the Washington University Diabetes Research Center (DRC) has a long-term goal of enhancing diabetes-related research at Washington University through the use of sophisticated services and technologies likely to contribute to discoveries that can be translated to novel treatments for diabetes and its complications. The three objectives of the Core are: 1) To provide phenotyping services to DRC members in order to facilitate NIH-funded diabetes/metabolism-related research and enhance the cost-effectiveness of that research; 2) To train DRC investigators in the maintenance and manipulation of mouse colonies relevant to diabetes and metabolic research; and 3) To develop new research capabilities to enhance the ability of DRC members to perform diabetes and metabolic research. The Core fulfills an important need in the diabetes research community with 52 DRC investigators utilizing services during the past funding period. Over this time frame, the Core provided extensive support that included more than 7,000 biochemical assays of serum, more than 4,400 determinations of mouse body composition, and more than 1,000 indirect calorimetry assessments in mice, to mention the services in greatest demand. Evidence of considerable Core evolution include: elimination of some services, institution of better defined quality control, expanded training to include rigorous approaches to normalizing energy balance and other issues (all in response to criticisms at the time of the last competitive renewal), addition of new instrumentation, upgrades to existing instrumentation, increased physical size of the Core, and improved operational flow. Over this current project period, Diabetes Models Phenotyping Core support helped users contribute a series of important scholarly advances with substantial potential for translation to improved care for people with diabetes.